On Thu, Feb 09, 2006 at 03:36:00PM -0500, Chris Howie wrote: > > Try booting the kernel with the "noapic nolapic" parameters.
Thanks Chris, this worked. I've been monitoring ntp on and off all day and noticed it was having to step the clock about -6 seconds every 5 to 10 minutes. I also would never get the "kernel time sync enabled 0001" message in my ntp log. The output of ntpq -p would show all three of my us.pool.ntp.org servers with offsets around -4000 and jitter of 2000+. I did some research on your noapic nolapic suggestion and found this thread on the kernel.org mailing list (1) which I think explains why this fix works and the problem it addresses. I'm not a kernel hacker but it seems to have to do with the nForce2 chipset and something called the "C1 halt disconnect fix." Apparently not all BIOS have this fix, in particular Abit boards (which I'm using) do not and Abit will not offer BIOS updates with the fix, according to the thread. The problem itself causes the interrupt timers to go awry and can result in even worse problems than just poor clock performance. After rebooting with the "noapic nolapic" kernel options ntp was able to sync rather quickly and server offsets are down to high 50's with jitters of less than 20. Anyway, the thread at kernel.org is here: (1) http://search.luky.org/linux-kernel.2005/msg01168.html I'd encourage those with NTP problems using motherboards with the nForce2 chipset to read the thread and give the "noapic nolapic" kernel options a try. If your experience will be anything like mine, you'll notice a dramatic improvement in NTP performance rather quickly. Thanks again Chris for the helpful suggestion. -- Ken Wahl
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